Distinct Soil Microbial Communities in habitats of differing soil water balance on the Tibetan Plateau

Yuntao Li,Jonathan Adams,Jin-Sheng He,Hao Wang,Yu Shi,Haiyan Chu

doi:10.1038/srep46407

Abstract

Global change may be a severe threat to natural and agricultural systems, partly through its effects in altering soil biota and processes, due to changes in water balance. We studied the potential influence of changing soil water balance on soil biota by comparing existing sites along a natural water balance gradient in the Qinghai-Tibetan Plateau. In this study, the community structure of bacteria, archaea and eukaryotes differed between the different soil water conditions. Soil moisture was the strongest predictor of bacterial and eukaryotic community structure, whereas C/N ratio was the key factor predicting variation in the archaeal community. Bacterial and eukaryotic diversity was quite stable among different soil water availability, but archaeal diversity was dramatically different between the habitats. The auxotype of methanogens also varied significantly among different habitats. The co-varying soil properties among habitats shaped the community structure of soil microbes, with archaea being particularly sensitive in terms of community composition, diversity and functional groups. Bacterial and archaeal phylogenetic community turnover was mainly driven by deterministic processes while stochastic processes had stronger effects on eukaryotic phylogenetic community turnover. Our work provides insight into microbial community, functional group and phylogenetic turnover under different soil conditions in low-latitude alpine ecosystem.

Highlights

The effects of permafrost melting on microbial processes have already been investigated to some extent
Combining the landscape-scale gradient sampling strategy with high-throughput sequencing results, we demonstrated that microbial community varied significantly between the three sets of soil water conditions on the Qinghai-Tibetan Plateau
It is indicated that in our study area, soil moisture was the main driving factor of bacterial and eukaryotic community, whereas the archaeal community was mainly affected by C/N ratio (Fig. 2; Tables S7 and S8; Fig. S3a–S3c)

Summary

Introduction

The effects of permafrost melting on microbial processes have already been investigated to some extent. There is little research analyzing the phylogenetic community turnover especially on Tibetan Plateau and only focusing on bacteria[32]. We know very little about the phylogenetic turnover pattern for archaea and eukaryotes on Tibetan Plateau. We conducted our study at Haibei Station in the Qinghai-Tibetan Plateau, to investigate the soil microbial communities for their diversity and community structure, and we looked into the relative role of deterministic and stochastic processes that governing their phylogenetic turnover. The comparative study included three different habitats with different soil water conditions and three different groups of microbes (bacteria, archaea and eukaryotes). Given above, this experiment was aimed to answer: (a). Do different kind of microbes share a same pattern in their phylogenetic community turnover?

Methods

Results

Conclusion